Northern Ireland's prisons could be filled to bursting point by plans to introduce open-ended sentences for the most serious offenders, campaigners have warned.
Lobbyists said the zero-tolerance regime in England had caused prison overcrowding and left a huge backlog of inmates waiting for their release to be considered.
They were speaking after the head of the Life Sentence Review Commissioners warned of a strain on resources. A spokesman for the Howard League for Penal Reform group, which monitors prisoners' treatment, said: "The problem is that you could have prisons full to bursting point.
"This is one of the changes which this Government has introduced which are simply unsustainable and have contributed to the prison problem we have in England."
Former Northern Ireland Office criminal justice minister David Hanson said last December that he would introduce non-determinate life sentences, meaning those committing the most serious offences like murder and rape could be detained indefinitely.
His intervention followed the case of Attracta Harron (65) of Strabane, Co Tyrone, murdered on her way home from Mass by Trevor Hamilton, 23, in 2003, less than four months after he completed a rape sentence.
The English reforms were introduced in April 2005 and there are 2,410 people there incarcerated indefinitely. "Anecdotally some prison governors are refusing to take them because of the disruption it causes to how the prison works," the Howard League added. Peter Smith, chairman of the Life Sentence Review Commissioners, gave evidence to the Northern Ireland Affairs Committee of MPs last week.
"The area of concern I would like to flag up is the impact on rehabilitation resources, including testing resources, of the advent of the proposed indeterminate public protection sentences," he said. "All the indications are (that it) will have a significant impact on prisoner numbers in Northern Ireland, and of course the cost simply of holding those prisoners in prison may impact, unless resources are made available, on the rehabilitation resources of the Prison Service."
SDLP Assemblyman Alban Maginness said the Government needed to proceed carefully. "The idea that we can introduce blanket indeterminate sentencing is incompatible with the good running of the Prison Service," he said. A spokeswoman for the NIO said: "We are currently preparing legislation and we will be looking to take account of experiences in England and Wales."